vlan: implement ndo_get_iflink

Don't use dev->iflink anymore.

CC: Patrick McHardy <kaber@trash.net>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 8b5ab90..01d7ba8 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -538,7 +538,6 @@
 	/* IFF_BROADCAST|IFF_MULTICAST; ??? */
 	dev->flags  = real_dev->flags & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI |
 					  IFF_MASTER | IFF_SLAVE);
-	dev->iflink = real_dev->ifindex;
 	dev->state  = (real_dev->state & ((1<<__LINK_STATE_NOCARRIER) |
 					  (1<<__LINK_STATE_DORMANT))) |
 		      (1<<__LINK_STATE_PRESENT);
@@ -733,6 +732,13 @@
 }
 #endif /* CONFIG_NET_POLL_CONTROLLER */
 
+static int vlan_dev_get_iflink(const struct net_device *dev)
+{
+	struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
+
+	return real_dev->ifindex;
+}
+
 static const struct ethtool_ops vlan_ethtool_ops = {
 	.get_settings	        = vlan_ethtool_get_settings,
 	.get_drvinfo	        = vlan_ethtool_get_drvinfo,
@@ -769,6 +775,7 @@
 #endif
 	.ndo_fix_features	= vlan_dev_fix_features,
 	.ndo_get_lock_subclass  = vlan_dev_get_lock_subclass,
+	.ndo_get_iflink		= vlan_dev_get_iflink,
 };
 
 static void vlan_dev_free(struct net_device *dev)